1. Field of the Invention
The present invention pertains to a device and method for measuring fluid flow into plural selected zones of an earth formation from an injection well whereby accurate measurement of the flow into each of the zones may be measured.
2. Background
In water and gas injection wells, it is common to inject such fluids into multiple, spaced apart earth formation zones simultaneously. However, in order to manage the production of fluids from a particular reservoir or the disposition of the injection fluids into selected earth formation zones, it is desirable to know the flow rate of fluid into each of the zones independently. Common practice in making this determination comprises lowering a tool into a well on an electric signal conducting cable or so-called E-line which tool has a small spinner or propeller type metering device mounted thereon and which is somewhat less than the diameter of the tubing through which the fluid to be measured is flowing. Accordingly, the accuracy of these so-called spinner type surveys is insufficient to effectively manage injection processes or to comply with certain regulatory requirements. Moreover, prior art measuring devices of the type mentioned above require relatively complicated and expensive support equipment and substantially continuous monitoring by operating personnel.
U.S. Pat. No. 4,928,759 to Siegfried et al and U.S. Pat. No. 5,018,574 to L. J. Smith, both assigned to the assignee of the present invention, describe devices adapted to measure fluid flow rates in production wells.
However, the present invention overcomes the deficiencies of prior art injection well flow measurement methods and devices as will be recognized by those skilled in the art from the following summarization and detailed description.